The Wine Rack by David Gray in Washington, DC is pitch dark (except for emergency lighting) at all times except during limited access hours.

Effect of Light

Light is another enemy of wine, as it is to beer, and many other beverages. The glass used to manufacture wine bottles is generally tinted. This is for more than aesthetics, as ultraviolet light will promote the chemical degeneration of fine wine. (Persons coming from regions of the country where Hood diary products are distributed, may have noticed that they now package their milk in opaque containers for the same reason -- to combat deterioration due to light.)

Light is energy, and energy introduced into wine will accelerate naturally occurring chemical reactions -- resulting in premature aging and development. Light also tends to generate heat, another reason to avoid storing in the presence of constant light. For this reason, avoid wine retailers who place unopened bottles of wine for display in direct sunlight. Store, to the extent practical, in the dark.